Twitter is celebrating its seventh birthday — the anniversary of when co-founder and current Twitter executive chairman Jack Dorsey sent out the first message — and has posted a celebratory video documenting its growth into a global communication platform. The video traces Twitter’s growth from concept to the introduction of its video service, Vine.

“Twitter has become a true global town square — a public place to hear the latest news, exchange ideas and connect with people all in real time,” wrote the company’s editorial director, Karen Wickre.

The company reported that it’s now seeing over 200 million active users send 400 million tweets per day, marking quite a bit of growth over the past year. On its sixth birthday last year, the company said it was seeing 340 million tweets per day.

The volume of tweets alone is impressive, but Twitter took care to highlight the kind of messages being spread through its network now — tweets from space, tweets about revolution and conversations between notable people that anyone can see. The company has invested a lot of time and effort, for example, in getting high-profile people to join its network, such as the former Pope Benedict, who handed his “@Pontifex” Twitter handle on to his successor, Pope Francis.

Notable names aside, Twitter has also come to play a role in starting and spreading the daily conversation — many of the highlights in the company’s video center around big stories such as natural disasters, major events such as the World Cup or the Olympics and political events such as the 2011 protest in Egypt's Tahrir Square.

As Twitter grows and continues to market itself as a place for free expression, the company has some tricky questions to answer — namely how to navigate speech laws in markets around the world.

As The Washington Post reported, Twitter has recently come under fire from a Jewish human rights organization, the Simon Wiesenthal Center, which claims that anti-Semitic hate speech is a growing problem on the site. Some of the hate speech highlighted in the center’s report is illegal in countries such as France and Germany, and is the sort of message for which Twitter developed a tool that lets the service censor tweets by country.

Twitter faced considerable backlash when it deployed those filters early last year; the company answered that criticism by saying it was a way to prevent having to remove the content from its network altogether.

The company also faces requests from world governments for information, which it says are typically made in connection with criminal investigations. Twitter said in January that it had received 1,009 requests from governments around the world in 2012, up from 849 in 2011.